A SYNTHETIC HUMAN EPIDERMAL MODEL CAN DIFFERENTIATE ACUTE FROM LATENT EFFECTS OF THE MONOFUNCTIONAL MUSTARD ANALOGUE, 2-CHLOROETHYLETHYL SULFIDE.

In this study, researchers at the United States Army Medical Research Institute of Chemical Defense and the State University of New York at Binghamton used the metabolic indicator alamar blue (AB) as a noninvasive, fluorescent probe to analyze the toxic effects of the monofunctional sulfur mustard analogue, 2-chloroethylethyl sulfide (CEES). Data from normal human epidermal keratinocytes (NHEK) exposed to an AB incubation time of 30 min indicated that the dye could accurately estimate cell number as low as 500 cells/well. To determine if AB could reflect toxic episodes to skin cells, confluent NHEK monolayers were exposed to CEES or Triton X-100 for 2 hr. An additional 2 hr incubation with AB demonstrated dose-dependent effects of these toxicants. A synthetic human epidermal model, EpiDerm, was similarly treated with CEES or Triton X-100 and the same samples were assayed with AB at 4, 24, and 48 hr postexposure. EpiDerm had many of the manifestations of in vivo skin including desmosomes, keratin filaments, lamella bodies, and intercellular lamellae. Although 4 hr were sufficient to render 80 mM CEES-treated EpiDerm samples nonviable, 48 hr were necessary to achieve a similar effect with samples treated with 8.0 or 0.8 mM CEES. Histologic analysis of 48 hr samples revealed complete separation of the EpiDerm from its underlying dermal substitute in specimens treated with 1% Triton X-100 (v/v), 9.0 mM CEES, and 0.8 mM CEES; both 48 hr control and 80 mM CEES samples showed no similar separations. These data, taken together, suggest that the epidermis/substrate separation induced by CEES in vitro is time-dependent and is not necessarily a consequence of CEES toxicity. The implication of this research is that a synthetic human epidermis (EpiDerm) and fluorescent indicator dyes can be used to compare the mechanisms underlying the acute vs. latent effects of sulfur mustard (HD) in vitro.

2-Chloroethylenthyl sulfide (CEES), a mustard agent, Alamar Blue, Endpoints, Alamar Blue, EpiDerm, Monofunctional, 2-chloroethylethyl sulfide (CEES), Mucin secretion, Mustard Analogue, Surfactants, Triton X-100, Triton X-100